Preparation of SrAl2O4: Eu, Dy Phosphor by Nano-Coating Process and Its Optical Properties

The SrAl₂O₄: Eu²⁺, Dy³⁺ phosphor nanoscale powders with high brightness were prepared by a nano-coating process. The resulted SrCO₃@ Al₂O₃ core-shell precursors were characterized by transmission electron microscope (TEM), which indicates that the precursor particles have narrow size distribution. The structure and optical properties of the phosphor powders were investigated systematically by means of X-ray diffraction (XRD) and spectroflourometer. It was found that the single-phase SrAl₂O₄ formed at 1000degC, which is approximately 300degC lower than that required for the conventional solid-state reaction. What is more, the impurity phase 3SrOAl₂O₃ can be completely removed by the present method. Also, the luminescence intensity is higher than that prepared by solid-state process in the comparable condition.